Die foe shaping single twist atjgeks



(ModeL) 2 Sheets-Sheet l.

D. S. HOLLEY.

DIE FOR SHAPING SINGLE TWIST AUGERS.

No. 331,708. Patented Dec. 1, 1885.

FIGJ- FIGJV- (ModeL) Sheets-Sheet 2.

D. S. HOLLEY.

DIE FOR SHAPING SINGLE TWIST AUGBRS.

Patented Dec. 1, 1885.

FEGMI FIG IX N PEIERS, PhomLnhn m mn Wislvingun. D. C.

ilnirnn I Srn'rns Parent @rrrcn.

DIVIGHT S. HOL-LEY, OF FISKDALE, MASSACHUSETTS, ASSIGNOR- TO THE SNELL MANUFACTURING COMPANY, OF SAME PLACE.

DIE FOR SHAPING SlNGLE-TWIST AUGERS.

SPECIFICATION forming part of Letters Patent No. 331,708, dated December 1, 1885.

Application filed April 30, 1885.

To all whom it may concern:

Be it known that I, DWIGHT S. HoLLnY, a citizen of the United States, residing at Fiskdale, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Dies for Shaping the Twists and Heads of Single-Twist Angers, of which the following is a specification.

In order that myinvention may be fully un- IO derstood, I will proceed to describe it with reference to the accompanying drawings, in which- Figures I and II are face views of the two corresponding crimpingdies. Figs. III and I 5 IV are end views of the same. Fig. V is a vertical sectional view of the two dies placed face to face. Figs.VI and VII are face views of two correspondinghalf-dies of the form preferably employed for supporting the auger while its head is being shaped. FigsJ III and IX are end views of the same. Fig. X is a vertical sectional view, showing the dies in closed po sition for shaping the head of a single-twist auger shown in dotted lines. Fig. XI is a 2 5 face view of the punch.

My invention relates to improvements in dies for manufacturing single-twist angers, which are distinguished from double-twist an gers as follows:

A doubletwist anger is commonly formed by twisting a flat piece of metal, the result being the production of a blank having a solid central core or axis,from the diametrically-op posite sides of which project two sectional ribs running spirally from end to end, and

consequently a pair of grooves of corresponding shape. The dies for truing this blank and holding it while the end is being swaged into the desired shape require two parallel sectional ribs,which run spirally from end to end of said dies and are diametrically opposite each other. a clear space being left through the axis of the die for the central core of the auger.

A single-twist anger is formed of a single bar or strip of metal which is twisted into a spiral shape. Usually the inner edge of the strip does not extend to the center or axis of the auger, so that an axial space is left. The

5o consequent groove or channel is of course par- Serial nejicaosv. (ModeL) allel with and at any one point diametrically opposite the metalstrip. So far as I know,dies have never yet been employed for truing bits of this character and holding them while their ends are being swaged. It will be observed 5 that dies for this purpose will require but a single sectional rib running spirally from end to end, the consequent groove being parallel therewith and diametrically opposite. In this respect the dies for forming single-twist differ 6c from those for forming doubletwist angers.

It would appear to a casual observer that a double-twist die with onset its sectional ribs removed is in all respects the same as asingletwist die; but such is not the case. The difli- 6 culty existing in forming single-twist dies is due to the fact that the sectional rib must extend beyond the axis of the auger for the purpose of filling the hollow space, and for this reason the double-twist die with one sectional 7o rib removed would not answer the purpose.

The object of my invention is to overcome this difficulty; and to this end my invention consists of, first, a pair of dies which, when placed together, have a single sectional rib running spirally therethrough for the required distance; second, a pair of dies which, when placed together, have a sectional spiral rib extending beyond the axis of the auger being operated upon; third, :1 pair of (lies having a sectional rib whose lines of division are in planes outside of the axis of the bore of the dies; fourth, the combinatiomwith a pair of dies having a single sectional rib for holding a single-twist-auger blank, of a punch or die 8 for swaging the end thereof into the desired shape, and in details of construction hereinafter fully described and claimed.

A B are the two dies, each having a se1nicylindrical groove, A B, forming the bore, which is broken by teeth or projections D so curved that when the said dies are placed face to face said teeth will meet and form one con tinuous sectional spiral rib,which is designed to fit the groove of a single-twist auger, and when pressure is applied crimp it true. Vhen these dies are used for crimping only, the teeth are all made of the same size, and similar in form; but when they are employed for holding the blank while the end thereof is 109 being swaged into the desired shape by means of the punch or cylindrical die 0, the first tooth,D a (which forms the extremity of the continuous sectional rib,) is of such shape as to give the under side of the head the desired form. Form is given to the outside of the head by the punch G, which may be operated by a drop-press, hydraulic press, or otherwise.

It will be observed that the sectional spiral rib projects beyond the axis of the bore A B; hence it would be impracticable to divide the said rib in the same plane as the body of the die; or, in other words, in the axis of the bore A B. I do not desire to limit myself to any particular plane for dividing this rib, for I believe myself to be the first to so divide it. The manner adopted by me is to divide it in a plane transverse to the axis of the bore A B, whereby overlapping lips or extensions a I) 0, 850., are produced,which serve to guide the two sections A B as they approach each other. These lips or extensions are preferably strengthened by abutments a b c, &c.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent: 1. The combination of dies having teeth or projections which, when said dies are placed together, form a single continuous spiral rib, for the purpose set forth.

2. The combination,with a pair of dies each having a semicircular groove and teeth or projections which, when said dies are placed together, form a single continuous sectional spiral rib, of a die or punch for swaging the end of the blank, as set forth.

3. A pair of dies which, when united, have a cylindrical bore, and a sectional spiral rib within said bore whose lines of division are in planes outside of the axis of said bore, as set forth.

4. A pair of dies which, when united, have a cylindrical bore, and a sectional spiral rib within said bore whose lines of division are in planes transverse to the axis of bore, as set forth.

5. The combination of a pair of dies, A B, having teeth or projections D, lips or extensions a b c, 850., and abutments a'b c, &c., v

all constructed and arranged substantially as set fort-h. v

6. The dies having, when united, a cylindrical bore and teeth or projections,constitut- DWIGHT S. HOLLEY.

WVitnesses:

RUFUS E. BOND, J OHN F. HEBARD. 

